| .\" Copyright 1992, 1993 Rickard E. Faith (faith@cs.unc.edu) |
| .\" May be distributed under the GNU General Public License |
| .\" " for emacs's hilit19 mode :-) |
| .TH SIMPLEINIT 8 "20 November 1993" "Linux 0.99" "Linux Programmer's Manual" |
| .SH NAME |
| simpleinit \- process control initialization |
| .SH SYNOPSIS |
| .B "init [ single ] [ script ]" |
| .SH DESCRIPTION |
| .B init |
| is invoked as the last step in the Linux boot sequence. If the |
| .B single |
| option is used, or if the file |
| .I /etc/singleboot |
| exists, then single user mode will be entered, by starting |
| .IR /bin/sh . |
| If the file |
| .I /etc/securesingle |
| exists, then the root password will be required to start single user mode. |
| If the root password does not exist, or if |
| .I /etc/passwd |
| does not exist, the checking of the password will be skipped. |
| |
| If the file |
| .I /etc/TZ |
| exists, then the contents of that file will be read, and used to set the TZ |
| environment variable for each process started by |
| .BR simpleinit . |
| This "feature" is only available if it's configured at compile-time. It's |
| not normally needed. |
| |
| After single user mode is terminated, the |
| .I /etc/rc |
| file is executed, and the information in |
| .I /etc/inittab |
| will be used to start processes. |
| |
| .SH "THE INITTAB FILE" |
| Because of the number of init programs which are appearing in the Linux |
| community, the documentation for the |
| .I /etc/inittab |
| file, which is usually found with the |
| .BR inittab (5) |
| man page, is presented here: |
| |
| The format is |
| |
| .RS |
| .B bootprog=file |
| |
| .B fileprefix=string |
| |
| .B PATH=search path |
| |
| .B "ttyline:termcap-entry:getty-command" |
| .RE |
| |
| An example is as follows: |
| |
| .nf |
| .RS |
| bootprog = rc |
| fileprefix = /sbin/ |
| PATH = /sbin:/bin |
| |
| tty1:linux:/sbin/getty 9600 tty1 |
| tty2:linux:/sbin/getty 9600 tty2 |
| tty3:linux:/sbin/getty 9600 tty3 |
| tty4:linux:/sbin/getty 9600 tty4 |
| # tty5:linux:/sbin/getty 9600 tty5 |
| # ttyS1:dumb:/sbin/getty 9600 ttyS1 |
| # ttyS2:dumb:/sbin/getty -m -t60 2400 ttyS2 |
| .RE |
| .fi |
| |
| Lines beginning with the |
| .B # |
| character are treated as comments. Please see documentation for the |
| .B getty (8) |
| command that you are using, since there are several of these in the Linux |
| community at this time. |
| .SH SIGNALS |
| \fBsimpleinit\fP(8) responds to signals in a variety of ways: |
| .TP |
| .B SIGHUP |
| The \fI/etc/inittab\fP configuration file will be read again. |
| .TP |
| .B SIGTSTP |
| This flips a toggle, which controls whether more processes will be |
| spawned. |
| .TP |
| .B SIGINT |
| \fBsimpleinit\fP(8) will sync a few times, and try to start |
| \fBreboot\fP(8). Failing this, it will execute the system |
| \fBreboot\fP(2) call. Under Linux, it is possible to configure the |
| Ctrl-Alt-Del sequence to send a signal to the \fBinit\fP process |
| instead of rebooting the system (\fBsimpleinit\fP(8) does this by |
| default). |
| .TP |
| .B SIGQUIT |
| The \fBreboot\fP(8) programme is executed in place of the |
| \fBsimpleinit\fP(8) programme. This allows \fBreboot\fP(8) to cleanly |
| remount (read-only) the root filesystem, even if the old inode for the |
| \fBinit\fP process was unlinked. |
| .SH FILES |
| .I /etc/inittab |
| .br |
| .I /etc/singleboot |
| .br |
| .I /etc/securesingle |
| .br |
| .I /etc/TZ |
| .br |
| .I /etc/passwd |
| .br |
| .I /etc/rc |
| .SH "SEE ALSO" |
| .BR inittab (5), |
| .BR ctrlaltdel (8) |
| .BR reboot (8), |
| .BR termcap (5), |
| .BR getty (8), |
| .BR agetty (8), |
| .BR shutdown (8) |
| .SH BUGS |
| This program is called |
| .B simpleinit |
| to distinguish it from the System V compatible versions of init which are |
| starting to appear in the Linux community. |
| .B simpleinit |
| should be linked to, or made identical with, |
| .I init |
| for correct functionality. |
| .SH AUTHOR |
| Peter Orbaek (poe@daimi.aau.dk) |
| .br |
| Version 1.20, with patches for singleuser mode by Werner Almesberger |
| |